Q23 of 98 Page 314

For any two matrices A and B,

If the two matrices A and B are of same order it is not necessary that in every situation AB= BA

AB= BA = I only when A = B^-1

B=A^-1

Other time ABBA

If A is a 3-rowed square matrix and │A│=4 then adj(adj A)=?

If A is a 3-rowed square matrix and │A│=5 then │adj A│=?

If A =then A=?

If A is an invertible square matrix then │A^-1│=?